Improvement in preparing phosphoric acid as a substitute for other



withpcrcelain or other proper vessel.

UNITED STATES ATENT OFFICE.

a N. nonsr-onn, or CAMBRIDGE, MASSACHUSETTS.

IMPROVEMENT IN PREPARING PHOSPNORIC ACID AS A SUBSTITUTE FOR OTHER SQLID ACIDS.

Specificationformingpart of Letters Patent No. l4-3'2-2, dgted April 92, 1856.

To all echom it may concern: v

BeitknownthatI,EnENNon'roNHonsronD, of Cambridge, in the county of Middlescx and State of Massachusetts, have invented a. new

and improved preparation or substance, being a substitute for a pulvernlent acid, for use in the manufacture of soda-powders and other simiriol, and one thousand pounds of water. The

mass is stirred from time to timefor three days,

when ordinarily the action will be complete, and there will have resulted phosphoric acid, I superphosphates, and sulphate of lime, with a small proportion of salts of magnesia and soda. The pasty mass may be mixedwith flour or starch or any farinaceous substance while moist, and permitted slowly to dry in the sun or with the aid of artificial heat not above 150 Fahrenheit; or it may be mixed with freshly-burnt gypsum and then dried in the sun or by artificial heat; or it may be mixed with stearine or other fatty bodies and dried or the mass may beleached andtheconcentrated extract mixed with burnt gypsum or stearine and dried, all of which 1 have found to give desirable results; but the method which on the whole is to be preferred is the following: The pasty mass is leached and the extract concentrated to Baum in an evaporating-pan of cast-iron lined Ten gallons of this liquor are heated up to hoilin g and four pounds of perfectly white bone-ashes added, andith'e- 'hoiling continued until the wholeis reduced to a little less than half its original bulk, when the concentrated liquid mass, containing in solution the added boneashcs, becomes. pasty. The hot mass is then transferred to a convenient vessel to cool over night. In the morning following add to this concentrated pasty-mass seventy-six pounds of Wheaten flour, which isto be mixed to a uniform paste. Then add sixteen pounds of potato-starch and most carefully mix again,

after which it should turn out-friable, or in a state of division such that it maybe passed through a sieve with quarter-inch meshes. It

not sufficiently dry, it may be spread outa short time inthe sun or in a room heated to 1209 Fahrenheit. The sifted mass should then be broughtto a drying-chamber and spread out in trays until it becomes-brittle at a temperature of from to Fahrenheit,when the heatmay be raisedto from to Fahrenheit and continued till the mass is thoroughly dried. TVhen dried the preparation should be packed in close boxes or barrels to prevent the absorption of moisture.

The proportions of the agents employed may be varied somewhat without essentially atlecting the result. Oorn'starch and other farina' ceons substances-as rice-flour or farina-qn ay be substituted for wheaten hour and potatostarch. Bone-black may be used instead oi burned bones. v The object is to obtain available phosphoric acid in such form that it may be intimately mixed with dry alkaline carbonates or other sensitive chemical compounds without decomposing them or entering into combination with them, except upon the addi tion of moistuie or the application of artificial heat. This requires that the acid or acid phosphates be mixed with a neutral diluting agent,

as fiour or starch, to increase the extent of surface, that the action may be prompt when moisture or heat is applied, and at the same time to more or less invest the particles of acid to prevent them from action on contact while dry.

Prepared as above described,the article is white or grayish white, coarse-grained, may be readily pulverized, and with water may be stirred to an emulsion. It is exceedingly sour to the taste, but does not act when mixed with dry alkaline carbonates without the addition of water or the application of heat.

As a dry brittle powder the article has the advantages of a pulverulent acid, may be handied, weighed, cream tartar,

stirred, &c., astartaricacid or and as a substitute for these and a variety of similar pnlvernlent acids and acid salts has many uses in manufactures. It

may, among other uses, be mixed with dry alkaline carbonates, (carbonate of potassa or carbonate of soda,) and remain in this state without evolution of carbonicacid until moistened or heated, thus making it a substitute acid at will from a mixture ot'this puiwruleut for cream-tartar and tartaric acid in the prepnacid with ulkaiiue carbonates upon the addiration of yeast-powder 0r baking-powder. tion of moisture or heat, or both.

The acidified mixture prepared in aecord- T ubni "'Y). auce with the foregoing specification I have; 1 1 Ohm called pulverulenb phosphoric acid; and I In presence ofclaim this pulverulent phosphoric acid for ucu- UIIAUNOEY SMITH,

tralizingalknliue bases and roducingcarhonic \ViLLIAM RmuARpsoN. 

